1. Field of the Invention
The present invention relates to electrical connectors and more particularly to an electrical connector having a built-in device for providing surge suppressing protection for conductive circuits to which the connector terminals are electrically connected.
2. Description of the Prior Art
Electrical circuitry often must be protected from damage caused by power surges owing to electrostatic discharges (ESD) and electromagnetic pulses (EMP). The high voltage generated by ESD and EMP can damage voltage sensitive integrated circuits and the like. Means for protecting against power surges include the use of additional specialized circuitry within equipment, such as voltage variable resistors. Protection can also be achieved by the use of connectors or adapters having transient voltage suppressing and filtering devices therein, thereby eliminating the need for costly and extensive modification of the equipment itself.
While it is possible to design a new equipment with specialized circuits for protection from power surges, it is also desirable to provide protection for existing equipment and/or provide protection for sensitive electronic equipment. Often there is a need to interconnect a plurality of pieces of electronic equipment together. The equipment may be wired directly or interconnected through the use of one or more adapters. If the equipment itself does not have protection from power surges, or additional protection is desired, these adapters may be provided with such protection. Adapters with built-in transient suppression device are disclosed in U.S. Pat. Nos. 4,726,638 and 4,799,901.
U.S. Pat. No. 4,726,638 discloses a transient voltage suppression device consisting of a dielectric substrate with a ground surface area on a lower surface thereof, a plurality of transient voltage protectors mounted on an upper surface of the substrate and connected to the ground surface area through apertures in the substrate, and the ground plate attached to the bottom of the jack housing and contacting the ground surface area. The transient voltage suppressions are in the form of diodes and are connected to respective jack contacts via conductive paths on the substrate. The substrate is partially received in the housing to engage with the ground plate, which occupies significant space. Alternatively, the substrate is attached to the bottom of the housing, whereby the height of the modular jack is increased. Furthermore, the ground plate is individually attached to a bottom surface of the housing, which requires modification to the housing according to the specific configuration of the ground plate, thereby complicating manufacture and increasing production cost.
U.S. Pat. No. 4,799,901 issued to Pirc on Jan. 24, 1989 discloses a modular jack having transient voltage suppression protection. The Pirc connector comprises upper and lower housings, a first and second connector subassemblies, a transient voltage suppression members and a grounding shell. The first and second connector subassemblies include, respectively, first and second dielectric support members and first and second terminals. The transient voltage suppression members includes a circuit board having a plurality of electrical circuit components mounted thereon, and grounding strap having grounding legs extending through apertures in the circuit board. It is clearly that the structure of the Pirc jack is too complicated to be manufactured and assembled. Moreover, the first and second subassemblies and the housing means are provided separately, thus increasing manufacture processes of assembling the connector. Furthermore, as telecommunications devices have become more technologically advanced and integrated, requirements have become important for modular jacks providing multiplications of outlets. The housing and the grounding shell as disclosed in Pirc jack must be substituted when adding an extra outlet in the connector, which is a disadvantage to decrease the cost.
Hence, an electrical connector having an improved surge suppressing device is required to overcome the disadvantages of the prior art.